1. Field of the Invention
The present invention relates to dispensers, and more particularly, to a real-time dispenser fault detection and classification method for monitoring adhesive dots dispensed on a substrate by a dispenser.
2. Description of the Prior Art
A dispenser dispenses adhesive contained therein on a circuit board through a nozzle of the dispenser so as to form on the circuit board a plurality of adhesive dots for adhesively holding an electronic device. After a long period of operation, the nozzle of the dispenser is likely to be clogged with residues of the adhesive. Besides, the nozzle has to be so close to the circuit board while spraying the adhesive on the circuit board that the nozzle can touch the circuit board inadvertently and undesirably. As a result, the dispenser is susceptible to a nozzle jam characterized by distorted or disrupted adhesive jets, or displacement of the dispenser nozzle results in displaced adhesive jets.
In order to classify the aforesaid abnormalities of a dispenser, the prior art discloses judging the adhesive dot quality with the naked eye and determining whether the dispenser nozzle has to be changed or cleaned. Considering the need for automation and speedy production, the eye-based prior art is both unrealistic and cost-inefficient. More badly, an equipment engineer is unable to perform quality inspection on adhesive dots dispensed on a circuit board unless and until the dispensing of the adhesive dots is complete. In other words, whatever abnormalities a dispenser might have exhibited are not discovered by the equipment engineer unless and until the dispenser finishes dispensing the adhesive dots on the circuit board.